Photographic element for production of an immediate read-out as well as a permanent image

ABSTRACT

Light-sensitive photographic elements having, on a base sheet, a light-sensitive layer capable of providing a visible image directly upon exposure to light and also yielding a permanent image corresponding to such exposure upon subsequent photographic development.

United States Patent 1191 Farren et a1.

1111 3,840,372 1451 Oct. 8, 1974 [73] Assignee: GAF Corporation, New York, N.Y.

[22] Filed: Dec. 17, 1971 [21] Appl. No.: 209,358

52 us. 01. 96/68, 96/94, 96/119 PO 51 Int. Cl G03c 1/76, G030 3/00 58 Field 61 Search 96/94, 68, 87, 119 PO [561 References Cited UNITED STATES PATENTS 3,447,927 6/1969 Bacon ct a1 96/87 3,457,072 7/1969 Ditzer et a1. 96/27 3,458,317 7/1969 Ditzer 96/94 3,511,658 5/1970 Manko et al.... 96/68 3,574,625 4/1971 Bacon 96/94 FOREIGN PATENTS OR APPLICATIONS 1,184,063 3/l968 Great Britain Primary Examinn-Ronald H. Smith v Assistant Examiner-John L. 'Goodrow Attorney, Agent, or Firm-Walter C. Kehm; Samson B. Leavitt 1 57 ABSTRACT Light-sensitive photographic elements having, on a base sheet, alight-sensitive layer capable of providing a visible image directly upon exposure to light and also yielding a permanent image corresponding, to such exposure upon subsequent photographic development. v 1 1 1 Claim, No Drawings PHOTOGRAPHIC ELEMENT FOR PRODUCTION OF AN IMMEDIATE READ-OUT AS WELL AS A PERMANENT IMAGE This invention relates to photography, and especially to light-sensitive photographic elements suitable for the formation of print-out and developing-out images upon image-wise exposure to actinic light, and their use in photographic reproduction.

So-called print-out" elements are photographic materials having a light-sensitive layer which responds to the direct effect of exposure radiation to form a visible image. They are distinguished from so-called developing-out elements in that the latter require a develop ment treatment after photographic exposure to render the originally formed latent image visible.

Print-out materials have found useful application in the preparation'or reproduction of engineering drawings or diagrams involving successive recording and reproduction of letters,- symbols or other indicia one such procedure being the well-known Mergenthaler method. In brief, this method utilizes an apparatus having punch keys respectively corresponding to various images or indicia to be reproduced or recorded. When a key is activated, the corresponding character is projected as a light image on the recording sheet which can then be appropriately positioned and focused by the operator. By this procedure, engineeringdrawings can be composed in typewriter fashion by successively activating the desired keys and positioning and focusing the corresponding light images on a sheet of suitable photosensitive material. Accurate positioning of the characters is made possible by using print-out material as the recording material, so that a visible image is immediately formed, and the operator can adjust at once the relative position of the next character to be reproduced. A wide variety of print-out materials suitable for such use have been produced heretofore.

However, one of the principal objects of such reproduction methods is to provide in addition to an immediately visible image a permanent image, havingas distinguished from the print-out image stability against the image-degrading effectsof heat, humidity and the like, which normally cause fading or fogging of print-out images. Provision of a permanent image is especially important, since the image bearing sheet is usually intended to be used for repeated photographic exposure as a photographic master. Print-out images are generally not adapted to satisfy the requirements for such use, since, in view of the high speed characteristics required for their function, print-out emulsions are characterized by excessive fogging, loss of contrast and of density on aging.

It has been proposed heretofore to provide in printout materials employed for procedures of the type outlined above separate emulsion layers, one of which is a print-out emulsion and the other, an emulsion or layer adapted to provide a permanent copy when subjected to appropriate development treatment. Thus, in accordance with application Ser. No. 68,560, filed Aug. 31, 1970 of]. E. Bates et al, photographic materials are provided having in separate layers, a print-out emulsion and a developing-out emulsion, capable of re cording the same image upon exposure to light. Other photographic elements having such arrangement 'are disclosed in U.S. Pat. Nos. 3,442,648, 3,457,072 and 3,51 1,658.

, When light-sensitive material according to this inven-v tion containing such a composition together with :a sil- Thus, a principal object of this invention is to provide a photographic element capable of producing print-out images and developing-out images in the same lightsensitive layer. v

Another object of this invention involves the provision of a method of using the aforesaid photographic elements to form a visible image and a corresponding latent image with a single 'photograhic exposure. whereby upon subsequent appropriate development, the latent image is converted to a permanent image, characterized by-superior density, contrast, stability and reproducing quality when used as a master for further copies.

Other objects'of the invention will be apparent from the following detailed description.

Y The foregoing objects are attained in accordance with this invention by providing,' on a base sheet preferably a translucent or transparent'film base alight sensitive layer containing a mixture of a light-sensitive print-out silver halide emulsion, capable of yielding, photolytically, a visible image immediately upon exposure to actinic'radiation, and a light-sensitive composition which forms a latent image of the developing-out type upon exposure to actinic radiation, adapted to be rendered visible by appropriate photographic development.

Light-sensitive print-out emulsions contemplated for use in the light-sensitive materials of this invention are silver halide emulsions well known inthe art for printout materials. They are silver halide emulsions yielding a visible image immediately by photolytic reaction upon exposure to actinic radiation. They are especially emulsions of high internal sensitivity. Suitable print-out emulsions are, for example, those of the ammoniacal type especially the ammoniacal bromide type prepared by reprecipitation of silver chloride-bromide emulsion during the after-ripening step. Such emulsions are described, for example, in U.S..Pat. Nos. 3,039,871, 3.047392, 3,109,737 and 3,123,474, as well as in U.S. Pat. application Ser. No. 68,570 of Aug. 31, 1970, mentioned above.

A valuable aspect of this invention is the fact that it permits a wide selection of the developing-out composition contained in the light sensitive-layer. It should be noted that the expression developing out" composition as used herein is intended to denote photographic systems wherein a distinct operation is necessary to render visible the desired image, subsequentto the exposure to actinic radiation. Thus, the developing-out composition of the light-sensitive layers herein contemplated may be a high chloride content silver halide emulsion which is slow in speed and of high contrast.

ver halide print-out emulsion in the same layer is exposed image-wise to actinic light, a visible silver image is immediately formed by the print-out emulsion component, and at the same time, a latent image is formed by the developing-out component, susceptible to conversion to a permanent silver image by conventional photographic development. This is advantageously effected by the usual processing in a conventional photographic developer, stop bath and fixing bath preferably using a low solvent type developer and limiting the development of the high speed internal sensitive printout emulsion thereby.

in layers of the latter type, it has been found that a ratio by weight of about 2 parts of developing-out emulsion to 3 parts of print-out emulsion yields optimum results for both functions. This ratio can be varied by increasing the proportion of print-out emulsion to 4 parts (for 2 parts of developing-out emulsion). For optimum results, the concentration of silver in the lightsensitive layer should be within the range of 2 5 g. per sq. meter. I

As an alternative to conventional development of the latent image formed by the developing-out emulsion,

the layer can be processed after image-wise exposure to actinic radiation to produce a diffusion-transfer image. This involves surface contact of the exposed layer while moistened with a developer solution with a transfer sheet containing a nucleating reagent as disclosed in U.S. Pat. No. 2,352,014. In this way, the unexposed areas of the. light-sensitive layer yield their silver halides of the developing-out composition to the transfer sheet and, are therein converted to a silver image constituting a positive reproduction of the original light exposure. I

If a wash-out relief image is desired as the permanent image, the developing-out composition employed in the light-sensitive layer of this invention may be a bichromate sensit-ized gelatin optionally including a pigment to increase contrast in the resulting relief image. Such wash-out compositions are described, for example, at pp. 569 671 in Photographic Chemistry Glafkides (Fountain Press London 1958-60); pp. 225-230 in Photographic Facts and Formulae Wall & Jordan (American Photographic Publishing Co. Boston 1940). Development is effected 'in the case of such compositions by washing with warm water, whereby the unexposed portions of the layer are removed. 7

Instead of bichromated gelatin, the developing-out composition may contain instead of photosensitive polymer or -polymer-forming composition which undergoes a photolytically induced polymerization or hardening when exposed to actinic radiation after which the unexposed areas are removed by subjecting the exposed surface to an appropriate selective solvent. In general, suitable photopolymerizable compositions contain one or more monomeric substances generally vinyl type monomers together with a reagent capable of liberating a polymerization initiator when exposed to actinic radiation. Light-sensitive photopolymerizable compositions useful in the lightsensitive layers of the present invention are those described for example in U.S. Pat. Nos. 3,101,270, 3,041,172, 3,234,021 and 3,050,390.

Alternatively, there may be used as the developingout composition of the light-sensitive layers of the present invention, light-sensitive diazo compositions with or without an azo coupling compound, and hence, developable by the so-called dry or wet process, well known in the diazotype reproduction field. Wet processing involves use of a composition containing a light-sensitive diazo compound which is destroyed by exposure to light inthe desired image areas, whereupon the residual diazo compound in the unexposed areas is developed by treatment: with an alkaline developer containing an azo coupling compound to form a positive azo dye image. In the case of dry developing diazotype compositions, the azo coupler'is included in the light-sensitive composition which is stabilized against premature coupling prior to development, and after image-wise exposure to light, development is effected by treatment with an alkalinedeveloper such as ammonia vapor.

The developing-out composition of the layers of this invention may be such as to produce a positive reproduction of the original as in the caseof diazotype compositions, or a negative reproduction as in the case of conventionally developed silver halide compositions, photopolymerizable components or bichromated gelatin. Thus, as a further positive reproducing composition, there may be employed an autopositive emulsion utilizing the Herschel effect for reversal. Emulsions of this type are described, for example, in U.S. Pat. No."2,857.,273 and at p. 215 of Glafkides Photographic Chemistry. I

v The developing-outcomponent may likewise be provided by incorporation in the light-sensitive layers of this invention ofa light-sensitive electrostatic composition in particular, a finely divided photoconductive material such as zinc-oxide dispersedin as insulating resinous medium as a binder. The latter may be a water-insoluble resin, dispersed in latex, form in an aqueous dispersing medium, or the resin binder may be itself water-soluble, forming an aqueous dispersing medium for the photoconductor. Suitable zinc oxide-resin compositions for the purpose of this invention are disclosed in U.S. Pat. Nos. 3,248,216; 3,002,835; 2,986,467; 3,095,301; and 2,811,465. A latex dispersion'containing zinc oxide as disclosed in U.S. Pat. No. 3,152,895 or a dispersion of zine oxide in a waterfsoluble resin as disclosed in U.S. Pat. No. 3,160,503 can be incorporated with the print-out composition to yield alightsensitive layer as contemplated in this invention. In using such layers, an electrostatic charge is uniformly applied, e.g., by exposure to a corona discharge, prior to exposure to actinic light. When subjected to imagewise light exposure, the print-out component provides an immediate visible image, while the electrostatic charge on the surface of the photoconductoris discharged in the light-exposed areas, whereupon the residual electrostatic image is developed by treatment with a pigment toner, selectively attracted or repelled by the residual charge. The toner may be applied in dry powder form or as a suspension in vehicle.

When componentsother than silver halide compositions are used as the developing-out portion of the light-sensitive layers of this invention, suitable proportions as between the total solids of the print-out and developing out components of the layer generaly range from 2:1 to 1:2 by weight. 7

As noted above, the light-sensitive materials of this invention may be advantageously employed in photocomposing drafting procedures often referred to as the Mergenthalermethod. In, such processing, the light-, sensitive sheetmaterial of this invention is positioned in the exposure apparatus so as to receive imaging radiation. The operator successively activates punch keys,

an insulating liquid whereby a light pattern corresponding to each key is focused on the light-sensitive surface. For each exposure, the print-out emulsion yields a visible image of photolytic silver, and the developing-out emulsion or component forms a corresponding developable latent image. Since the operator is able to see the image of each exposure, he can readily position and focus the next exposure in relation to the preceding one. The latent images are then developed to provide a permanent record.

Should it be desired to remove the photolytic silver image formed by the print-out composition, this can be done by treating the material after development of the latent image of the developing-out composition with a silver bleaching solution such as potassium ferricyanide,-potassium bichromate, or any of the other silver bleach solutions known in the art. Such bleaching treatment does not impair the quality of the developing-out image, since the latter is much higher density than the print-out image.

The base sheet employed for the light-sensitive materials of this invention is preferably a transparent or translucent film, such as polycarbonate, polyester, cellulose acetate, cellulose acetate-butyrate or regenerated cellulose, or alternatively, a transparentized fibrous support such as paper impreganted with polypropylene. Such sheet materials are used when the permanent developed image is to be used as a photographic master. However, since only a single light-sensitive layer is applied, an opaque support such as ordinary paper or opaque film can be used when it will not interfere with the intended use of the develped material.

Our invention will be more fully understood from the following examples, wherein parts and percentages are by weight and temperatures are in degrees Centigrade, unless otherwise indicated.

EXAMPLE 1 A. A print-out emulsion was prepared as follows: A solution having the following composition wasprepared at 48C KBr 16.8 Kg. NaCl 26.4 Kg. Gelatin 6.0 Kg. Water 270 Liters The following solution was added to the foregoing, with agitation, over a period of about 1 /2 minutes:

AgNO 77.8 Kg. NH,OH(2871 NH 86 Liters Water 282 Liters After a pause of 6 minutes, a solution of 54 Kg. KBr in 120 Liters of water was added at 48C.

There were added 225 Liters of 50 percent aqueous ammonium sulphate, the emulsion was allowed to settle, and decanted to 200 Liters. After washing four times each time with 690 Liters of water, and each time decanting to 200 Liters. A solution of 54.75 Kg. gelatin in 1 l0 Liters of water was added. This solution had been prepared by soaking the gelatin 20 minutes, heating to 55 and cooling to 40C. After digesting minutes, there was finally added at 40C. a mixture of 46.05 Kg. 10 percent aqueous sulfamic acid and 1.492 Kg. 10 percent aqueous Kl solution. The emulsion was then digested at 505C for 28 minutes.

NuCl

CdCl 6.48 Kg. Kl (aqueous 10% Soln.) 0.88 Liter NH SO H (aqueous 10% Soln.) 6.48 Liters Water 102 Liters The foregoing was added at 48C to a solution of 7.76 Kg. gelatin in 416.16 Liters of water, prepared by allowing the gelatin to swell for 20 minutes and then heating to 48C. After 2 minutes, there was added a solution of 25.92 AgNO in 259.08 Liters of water at 44C. The resulting emulsion was dumped, digested for 20 minutes, cooled to 45C and then 260 Liters of 50 percent aqueous ammonium sulphate were added. The emulsion was then cooled to 27C, decantedto 280 Liters, and washed three times 7 each time with 690 Liters of water, and decanted each time to 280 Liters. There was then added a solution of 19.4 Kg. gelatin in a mixture of 12.96 Liters'of 10 percent aqueous sulfamic acid and 8.68 Liters of 10 percent aqueous NaCl the gelatin being allowed to swell in the solution for 30 minutes, melted at 40C and digested for 15 minutes. The resulting emulsion is then after-ripened for 60 minutes at 45C with addition of 1.34 Liter of 0.65 percent aqueous Kl, andfinally, 12.96"Liters of 10 percent aqueous CdCl Two parts by weight of the print-out emulsion (A, above) and one part by weight of the developing-out emulsion (B, above) were mixed, with addition of about 0.5 percent saponin as a coating aid. About 1 Y percent chrome alum may also be'added as a hardener.- The mixed emulsions were then coated on a subbed polyester film'base to a density of from 2 to 5 g. silver per square meter. Since neither the print-out emulsion nor the developing-out emulsion was'optically sensitized, all manufacturing operations as well as the coating were carried out under bright red safe-light conditions. 1

After drying, the light-sensitive coated material was placed in a suitable holder, and exposed for 2 seconds under a metal mask having an image-forming aperture therin, to a high intensity mercury arc lamp about 1 inch from the light-sensitive surface. A reproduction of the image aperture became visible in red safe-light through photolysis of the print-out emulsion component. Additional images can be added by successive exposures under other masks. The film is then developed for 2 minutes at 20C in GAF Reprodol" developer, fixed for 5 minutes in GAF Surfix" fixer, washed 10 minutes in water and dried. There resulted a strong silver image in the light-exposed areas, produced by development of the exposed developing-out emulsion.

Should it be desired to remove the print-out image, this can be done by treatment for 3 4 minutes with a reducing solution prepared by mixing a solution of 1 g. K Fe(CN) in 25 ml. water with a solution of 24 g. Na S O in 900 ml. water, washing and drying.

EXAMPLE 2 The procedure of Example 1 was repeated, except that the print-out and developing-out emulsions were formulated as follows: i

Ag NO 380 g. HNOu (10%) 40ml. NH,OH (28%) 420 ml. Water 1.4 Liter The above solution was added within 2 minutes to a solution of the following composition:

NaCl 140 g. KBr 84 g. Gelatin 30 g. Water 1.35 Liter After minutes, a solution of 200 g. KBr in 600 ml. water was added. After standing 15 minutes, the emulsion was precipitated by adding 3 Liters of 50 percent aqueous ammonium sulphate. After cooling to 25C the emulsion was decanted to 4 Liters, and washed twice each time with 8.0 Liters of water, decanting each time to 4 Liters. 250 g. of gelatin were then added, and the emulsion heated to 55C. It was then cooled'to 40C digested for 15 minutes, and ripened for 30 minutes at 40.5C. The emulsion'was then cooled to 40C and 230 ml. of percent aqueous sulfamic acid and 50 ml. of 10 percent aqueous K] were added. After standing 10 minutes, 350 ml. of 10 percent aqueous KBr solution were added.

B. To prepare the developing-outemulsion, there was added to a solution of 20 g. gelatin in 1.04 Liter water at 48C a solution of the following composition:

NaCl 16 g. CdCl 16 g. Kl (10% aqueous soln.) 2 ml. H 50 (10% aqueous soln.) 16 ml. Water 250 ml.

to 25 40.5 g. of gelatin were added,'.and after warming to 42C the following ingredients were added:

citric acid (10% aqueous soln.) 32 ml.

NaCl (10% aqueous soln.) 20 ml. K1 (1% aqueous soln) 3 ml. CtlC'l, (10% aqueous soln.) 10 ml.

After ripening 6 minutes at 48C, 30 ml. of 10 percent aqueous CdCl solution were added.

The print-out emulsion (A, above) and the developing-out emulsion (B, above) were mixed in the same proportions as in Example 1, and coated with addition of a coating aid and hardening agent on a polyester film base, and dried. The resulting material was similar in its properties and function to the material of Example l.

lnstead of conventional development of the image formed in the developing-out component as described in Example 1, a diffusion transfer copy can be made following the light exposure, by contact of the exposed layer while moistened with a photographic developer solution with a transfer'sheet of which the contacting layer contains a nucleating reagent. A positive image of the exposure is thereby produced on the transfer sheet.

lnstead of the developing-out emulsions of the foregoing Examples, there can be substituted autopositive emulsions, diazotype compositions, bichromated gelatin, photopolymerizable monomers or polymers, dispersions of photoconductive zinc oxide with an appropriate resin binder, or other developing-out compositions allas indicated in the description preceding the Examples.

Variations and modifications which will be obvious to those skilled in theart can be made in the foregoing compositions and procedures without departing from ratio of the solids of said print-out emulsion to those of said developing-out emulsion being approximately 3:2 to 4:2, and the amount of silver in said layer being from 2 to 5 g. per square meter. 

1. LIGHT-SENSITIVE PHOTOGRAPHIC MATERIAL HAVING, ON A BASE SHEET, A SINGLE LIGHT-SENSITIVE LAYER CONSISTING ESSENTIALLY OF AN ADMIXTURE OF A LIGHT-SENSITIVE SILVER HALIDE PRINT-OUT EMULSION CAPABLE OF YIELDING PHOTOLYTICALLY A VISIBLE IMAGE IMMEDIATELY UPON EXPOSURE TO ACTINIC RADIATION AND A LIGHT-SENSITIVE DEVELOPING-OUT SILVER HALIDE EMULSION CONTAINING A PREPONDERANCE OF SILVER CHLORIDE CAPABLE OF FORMING A LATENT IMAGE UPON SUCH OF SILVER CHLORIDE CAPABLE OF FORMING A LATENT IMAGE UPON SUCH EXPOSURE, SUCH LATENT IMAGE BEING SUSCEPTIBLE TO SUBSEQUENT DEVELOPMENT TO RENDER IT VISIBLE, THE WEIGHT RATIO OF THE SOLIDS OF SAID PRINT-OUT EMULSION TO THOSE OF SAID DEVELOPING-OUT EMULSION BEING APPROXIMATELY 3:2 TO 4:2, AND THE AMOUNT OF SILVER IN SAID LAYER BEING FROM 2 TO 5 G. PER SQUARE METER. 